Every Muslim knows that the key to Paradise is the statement, "There is none worthy of worship except Allah." Yet too many Muslims simply rely upon this statement and believe that as long as they have made this statement, nothing will harm them. They think will be granted Paradise because of this mere verbal statement of the Shahadah.
There is no question that the mere saying of," I bear witness that there is none worthy of worship except Allah and I bear witness that Muhammad is His servant and messenger," is not sufficient for salvation. In fact, the hypocrites used to make this statement quite often yet Allah describes them as liars and says that they shall abide in the lowest abyss of the Hell-fire.
As many scholars state, though, this statement or testimony is the key to Paradise. The famous Follower Wahb ibn Munabbih was once asked, "Isn't the statement of la ilaha illa-llah the key to Paradise?" He answered, "Yes, but every key has ridges. If you come with the key that has the right ridges, the door will open for you. Yet if you do not have the right ridges the door will not open for you." That is, it is saying [while meeting] certain conditions. These conditions are what will differentiate the person who will benefit from his making of that statement from the one who will not benefit from that statement, no matter how many times a day he may have made that statements.
Before discussing the conditions of the Shahadah, there is one more point that I feel compelled to make. That is, some people have a tendency to take one hadith or one verse and then based on that one text, they will make some conclusion that, for example, whoever simply says, "There is no God except Allah," will enter Paradise. But, actually, we should all realize that all of the Quran and Hadith complement each other and explain one another. To find the correct position on any one question, one must bring together all of the related verses and hadith and see what the true Islamic position is of that question. The same is true for the conditions of the shahadah.
If we study the verses of the Quran and the Hadith of the Prophet (peace be upon him), we will find that the conditions of the shahadah are seven, eight or nine in number depending on how we look at them. It is important that all of us make sure that we are meeting these conditions in our own lives and in our own testimony of faith. We must do our best to satisfy these conditions before it is too late and our testimony will be no avail whatsoever. It is not simply for the sake of teaching these conditions. Indeed, there is no benefit to that. But it is, instead, for all of us to look to ourselves and to make sure that we are actually meeting these conditions so that, by Allah's mercy, the doors to Paradise will be open for us by our key of la ilaha illa-llah.